Cementing shoe



Nov. 7, 1939.

H. K. PIEPER I CEMENTING SHOE Filed May 31, 1938 ii vlllllrllll wwvvgg/vv Patented Nov. 7, 1939 UNITED STATES ,CEMENTING SHOE HowardK. Pieper, Long Beach, Calif., assignor to E. B. Hall, V. P. Baker, and A. L. Armentrout Application May e1, 1938, Serial No. 210,835

10 Claims.

This invention relates to well tools and relates more particularly to devices for use in cementing casings in wells. A general object of this invention is to provide a practical and effective cementing shoe that materially facilitates the efflcient cementing of a casing in a well.

Another object of this invention is to provide a cementing shoe that assures the distribution of the cement or cement slurry throughout the circumference of the shoe and easing, thus preventing channeling.

Another object of this invention is to provide a cementing shoe embodying means for discharging or depositing the cement slurry a considerable distance below the lower end of the casing so that the cement slurry displaces the mud, etc., from the lower part of the well to pass upwardly around the casing and so that the cement slurry completely occupies the lower portion of the well to form a body of plastic cement into which the shoe and casing may be lowered to produce an effective fluid tight cement job or seal.

Another object of this invention is to pro- .vide a cementing shoe of the character mentioned that may operate as a float shoe to float the easing into the well.

Another object of this invention is to provide a cementing shoe of the character mentioned that is effective in washing away or removing bridges and other obstructions in the well.

Another object of this invention is to provide a cementing shoe of the character mentioned in which the tube element for depositing the cement slurry in advance of the lower end of the-casing may enter the rat-hole of the well to assist in locating or centering the casing in the well.

A further object of this invention is to provide a cementing shoe of the character mentioned that is inexpensive to manufacture and that is simple and convenient. to employ or operate.

The various objects and features of my 'invention will be fully understood from the following detailed description of a typical preferred form and application of the invention, throughout which description reference is made to the accompanying drawing in which:

Fig. 1 is a fragmentary vertical sectional view of the lower portion of a typical well showing the well casing and the body of the cementing shoe in vertical cross section and illustrating the tube element and piston in their raised positions. Fig. 2 is a view similar to Fig. 1 illustrating the tube element in its extended or projected position. Fig. 3 is an enlarged fragmentary vertical detailed sectional view of the piston means and Fig. 4 is an enlarged frag-' mentary vertical detailed sectional view of the valve and the adjacent parts.

The device or shoe of the present invention is intended primarily to facilitate the cementing .of a well casing in a well such as an oil well or gas well. In the drawing I have shown the lower portion of a typical well W and a casing C extending into the 'well. It will be assumed that the drilling operations are completed or suspended and that the casing C is in condition to be cemented in the well W.

The improved cementing shoe of the present invention may be said to comprise, generally, a body l applied to the lower end of the casing C, a shiftable pipe or tube element ll extending through the body l0, valve means l2 associated "with the tube element II and a piston I3 on the tube element II to be acted on by fluid or cement slurry under pressure to project the tube element H in advance of. the shoe body Ill.

The body Ill of the cementing shoe is intended to be attached to the lower end portion of the well casing C and is provided to directly and indirectly carry the other parts of the shoe. In the typical form of the invention disclosed in the drawing the shoe body l0 includes a tubular outer part l4 and an inner part I5. The outer part l4 may be threaded on the lower end portion of the casing C to extend downwardly beyond the casing: The internal diameter of the outer body part I4 is preferably substantially the same as that of the casing C. The inner body part I5 is secured in the projecting lower portion of the outer part It. The inner part I5 is a plug-like member and is preferably formed of frangible or drlllable material so that it may be broken out or drilled up by drilling tools or the like at the completion of the cementing job and following the hardeningof the cement. In the drawing I have illustrated the inner body part l5 formed of cementitious material, it being obvious that it may be formed other material-capable of being drilled out by drilling tools. When the part I5 is formed of cementitious material it may be molded or cast directly in the outer body part I4. The upper end of the part l5 may be flat and generally horizontal and the lower end of the part I5 is tapered or rounded to assist in guiding the casing C through the well W.

A central longitudinal opening I6 is provided in the inner body part I5 and. is lined with a suitable liner or guide IT. The guide I! may be molded or cast directly in the body part I5 and is preferably formed of a drillable material such as Bakelite, aluminum, aluminum alloy, or the like. The guide I1 is tubular having a central longitudinal opening I8. The opening I8 is considerably smaller in diameter than the opening of the outer body part I4 and the opening of the casing C.

The tubular element II is provided primarily to conduct the cement slurry into the lower end portion of the well W below the casing C and when occasion arises the tube element II may be employed to assist in washing out and removing bridges and obstructions in the well and in centering the casing C in the well. The tube element I I is slidable or shiftable vertically in the opening I8 of the guide I1 and extends completely through the opening I8 to project above and below the inner body part I5. The length of the tube element II depends upon various factors and conditions of operation. In most instances it is preferred to make the tube element II of substantial length to project a considerable distance beyond the shoe body II] when in the extended condition so that it may deliver the cement slurry to the bottom portion of the well W well in advance of the shoe body and the casing C. The element I I may be formed of one or more lengths or sections of tubular stock or pipe and is preferably uniform in external diameter. It is preferred to construct the tube element II of a drillable material such as aluminum, aluminum alloy, or the like. The tube element I I extends through the guide opening I8 with substantial clearance to allow the passage of fluid through the opening for the purpose to be hereinafter described.

The valve means I2 is provided to prevent the.

entrance of fluid from the well W to the casing C when the casing is to be floated into the well and the valve means I2 further serves to prevent a return flow of the cement slurry into the casing C when the cement has been discharged into the well. In the typical embodiment of the invention illustrated in the drawing the valve means I2 includes a tubular valve cage I9 attached to the tube element I I. The cage I9 may be threaded on the lower end portion of the tube element I I. A ringlike valve seat 20 is arranged across the interior of the cage I9. The seat 26 may be clamped between the lower end of the tube element II and an upwardly facing internal shoulder 2I on the cage I9. A ball 22 is provimed inthe cage I9 and is adapted to seal upwardly against the seat 28 to close the lower end of the tube element II against the up-flow of fluid.

A retainer ring 24 is threaded in the lower portion of the cage I9 and has inwardly and upwardly projecting fingers 23 for supporting the ball 22 so it does not close the cage I9 against the down flow of fluid therethrough. The cage I9, the seat 20, the ball 22 and the ring 24 are preferably formed of a material that may be broken up or drilled up by drilling tools or the like operated in the well W. The cage I9 is preferably, though not necessarily, larger in external diameter than the tube element I I. In the case where the .well W has a rat-hole (not shown) the cage I9 and the lower portion of the -tube element I I may enter the reduced rat-hole to center or locate the casing C in the lower portion of the well.

The invention may further include a downwardly facing annular valve seat 25 on the lower end of the guide I! and an upwardly facing valve face 26 on the cage I 9. The face 26 is adapted to cooperate with the seat 25 to prevent the entrance of well fluid to the opening I8 and the interior of the casing C when the casing is being run into the well W. The seat 25 and the face 26 may be suitably bevelled, as illustrated. The valve face 26 may be provided on the upper side of an annular flange 21 formed on the valve cage I9. It will be observed that the cooperation of the valve face 26 with the seat 25 serves to limit the upward movement of the tube element II with respect to the body Ill.

The piston I3 is provided on the tube element I I to be acted on by fluid or cement slurry under pressure in the casing C to move the tube element II to its extended position. The piston I3 is preferably provided on the upper end of the tune element I I to operate in the casing C. In the typical preferred form of the invention disclosed in the drawing the piston I3 includes a tubular part or extension 28 on the upper end of the tube element II. The extension 28 is larger in diameter than the tube element II and is connected or joined with the upper end of the element II by a wall part 29 that is tapered downwardly and inwardly relative to the longitudinal axis of the element. It will be observed that the tubular extension 28 and the wall part 29 form a funnel-like structure on the upper end of the tube element II. This funnel-like structure is efiective in directing fluid and cement slurry downwardly into the tube element I I.

The piston I3 further includes one or more sealing elements or cup leathers 30 on the extension 28. The cup leathers '36 are arranged around the extension 28 and are proportioned to slidably seal with the internal wall of the casing C. In the drawing I have shown a plurality of cup leathers 30 spaced apart by suitable spacers 3|. The cup leathers 30 may be formed of leather, rubber, fabric or combinations of such materials. A ring 32 is arranged around the extension 28 at the upper side of the uppermost cup leather 30 and bears upwardly against an annular flange 33 on the extension 28. A spacer 3| is arranged around the extension 28 to engage upwardly against the lowermost cup leather 3!]. Screws 35 are passed downwardly through circumferentially spaced openings in the flange 33, the ring 32, the cup leathers 30 and the spacers 3I and are threaded into openings in a ring 34. The ring 34 engages against the lowermost spacer 3| and the heads of the screws bear against the upper side of the flange 33.- 'I'hescrews 35 serve to hold the assembly of the cup leathers 30, the spacers 3| and the rings 32 and 34 on the extension 28. The spacers 3|, the rings 32 and 34 and the screws 35 are preferably formed of a material or materials that may be readily broken up or drilled up by drilling tools operated in the well. The cup leathers 39 have their open sides or concave sides facing upwardly to be acted on or expanded by seat 38 the piston I3 may be within or partially within the outer body part I4 and the tubeele: ment II is fully projected fromthe shoe body III as illustrated in Fig; 2. It will be noted that the piston I3 is considerably larger in externalv diameter than the tube I I, and the piston I3 and the wall part 29 present upwardly facing surfaces to be acted on by fluid under pressure in the casing C so that the fluid pressure moves the element II downwardly. Thus the assembly of the tube element I I and the piston I3 constitutes what may be termed a difierential tubular piston movable downwardly under applied pressure above it while passing or conducting the fluid downwardly into the well WI In the operation or use of the cementing shoe provided by this invention the shoe body I is secured to the lower end of the casing C prior to the introduction of the casing to the well W. When the casing C is lowered into the well W the hydrostatic pressure on the fluid in the well acts to maintain the ball 22 in its closed position against the seat 20 and acts to hold the tube element I I in its retracted or up position illustrated in Fig. 1 of the drawing. The ball 22 cooperating with the seat 29 and the face 26 cooperating with the seat 25 serve to prevent the entrance of well fluid to the casing C so that the shoe serves as a float shoe to float the easing into the well. The casing C is lowered to a position where the shoe is some distance above the bottom of the well W. It is preferred to lower the casing C to a position where the cage I9 on the lower end of the element I I will be clear of the bottom wall of the well when the tube element II is fully projected. In the event that bridges or other obstructions are encountered when the casing C is being run into the well W water or other fluid under pressure may be pumped down through the casing to discharge under pressure from the cage I9. The fluid under pressure acting on the piston I3 moves the tube element II downwardly with respect to the body I0 and projects the element from the shoe body. Fluid that may be trapped in the casing C and the body part I4 below the piston I3 is free to discharge downwardly through the clearance space in the opening I8 during the downward movement of the piston. The fluid under pressure discharging from the casing C in a jet or confined stream is effective in washing away or breaking down the bridges or obstructions in the well.

When the casing C has been lowered to the selected position, as described above, the cement slurry is passed or pumped downwardly through the casing C in the usual manner. The cement slurry under pressure acting on the piston l3 moves the piston and the tube element I I downwardly to a position such as illustrated in Fig. .2 of the drawing. When the piston I3 and the tube element II assume this position the cement slurry is discharged from the cage l9 at or immediately adjacentthe bottom wall of the well W. The cement slurry thus introduced into the lower end portion of the well W displaces the fluid and mud upwardly in the well and a uniformuncontaminated body of plastic cement or cement slurry is left in the lower portion of the well. When the required amount of cement slurry has been pumped into the well W, as just described the casing C may be lowered to its final position. When the casing C is lowered the body In and the lower portion of the casing enter or become immersed in the cement slurry occupying the lower portion of the well. The ball 22 cooperates with its seat 2|] to prevent the return of the cement slurry to the casing C. The shoe body III and the lower portion of the casing C moving downwardly into the body of cement slurry displace the cement slurry upwardly in the well.

will be apparent that the shoe body I0 and the lower portion of the casing C are completely embedded in a uniform uncontaminated body of the cement slurry when the above procedure is carried out. When the cement slurry has been allowed to set and harden suitable tools may be operated through the casing C to break out the body part I5, the tube element II, the piston I3, etc.", to leave the well open for further operations.

Having described only a typical preferred form and application'of my invention, I do not wish to be limited or restricted to the specific details herein set forth, but wish to-reserve to myself any variations or modifications that may appear to those skilled in the art or fall within the scope of the following claims.

Having described my invention, I claim:

1. A cementing shoe for use on a well casing comprising a shoe body for application to the casing, a shiftable tube projectable from the lower end of the body and adapted to conduct fluid from the casing to the well, and a piston on the tube adapted to be acted on by fluid under pressure in the casing to project the tube.

2. A cementing shoe for use on a well casing comprising a shoe body for application to the casing, the body having an opening, a shiftable tube element extending through the opening and adapted to conduct fluid from the casing to the well, and a piston on the tube element adapted to be acted on by fluid under pressure in the casing to project the tube element beyond the lower end of the body whereby the tube may dis-- charge the fluid into the well beyond the casing.

3. A cementing shoe for use on a well casing comprising a shoe body for application to the casing, the body having an opening, a shiftable tube element extending through the opening and adapted to conduct fluid from the casing to thewell, and a piston on the upper portion of the tube element operable in the casing to be acted on by fluid under pressure passed down the easing to project the tube element from the lower end of the body so that the tube elements discharges said fluid into the well beyond the body and the lower end of the casing.

4. A cementing shoe for use on a well casing comprising a shoe body for application to the casing, the body having an opening, a shiftable tube element extending through the opening and adapted to conduct fluid from the casing to the well, the tube element being smaller in diameter than the casing, and a piston tube element slidably sealing with the interior of the casing to be acted on by fluid pressure in the casing to move the tube element downwardly relative to the body to a position where it discharges the fluid into the well at a point below the lower end of the casing.

5. A cementing shoe for use on a well casing comprising a body for connection with the lower end of the casing, the body having a longitudinal opening, a tube shiftable in the opening and pro jectable downwardly from the lower end of the body, valve means associated with the tube to prevent an up flow therethrough and to allow a down flow therethrough, and a piston on the tube operable in the casing by fluid pressure in the casing to move the tube downwardly so that the gage discharges the fluid into the well below the y. 6. A cementing-shoe for use on a. well casing comprising a body for connection with the lower end of the casing, the body having a longitudinal opening, a tube shiftable in the opening and projectable downwardly from the lower end of the body, valve means associated with the tube to prevent an up flow therethrough and to allow a down flow therethrough, a valve part on the tube to seal off the opening when the tube is in the raised position, and a piston on the tube operable in the casing by fluid pressure in the casing to move the tube downwardly so that the tube discharges the fluid into the well below the body.

7. A cementing shoe for use on a well casing comprising a body for connection with the lower end of the casing, the body-having a longitudinal opening, a tube shiftable in the opening and projectable downwardly from the lower end of the body, valve means associated with the tube to prevent an up flow therethrough and to allow a down flow therethrough, a funnel part on the upper end of the tube for receiving fluid from the casing, and a piston associated with the said part to slidably seal with the interior of the casing whereby fluid pressure in the casing may act on the piston to move the tube downwardly with respect to the body.

8. A cementing shoe for use on a well casing comprising a shoe body for application to the casing, the body having an opening, a shiftable tube element extending through the opening and ,adapted to conduct fluid from the casing to the well, and a piston on the tube element adapted to be acted on by fluid under pressure in the easing to project the tube element beyond the lower end of the body whereby the tube may discharge the fluid into the well beyond the casing, the body, tube element and piston being formed of drillable material.

9. A cementing shoe for use on a well casing comprising a body including a tubular outer part to be secured to the casing and an inner part of drillable material having a longitudinal opening, a tube of drillable material shiftable in said opening and adapted to be projected beyond the lower end of the body, drillable valve means associated with the tube to prevent the upward passage of fluid therethrough and allowing the down flow of fluid therethrough, and a drillable piston on the tube operable in the casing by fluid pressure therein to project the tube from the lower end of the body whereby the tube is adapted to deliver the fluid to the well below the body and casing.

10. A cementing shoe for use on a well casing comprising a shoe body for application to the casing, the body having an opening, a shiftable tube element extending through the opening and adapted to conduct fluid from the casing to the well, and .a piston on the tube element adapted to be acted on by fluid under pressure in the casing to project the tube element beyond the lower end of the body whereby the tube element may discharge the fluid into the well beyond the casing, the tube element being of substantial length to discharge the fluid into the well a considerable distance below the body.

' HOWARD K. PIEPER. 

